1. Coulomb of charge (electrons) Think of it as a “bag of electrons” (containing 6000000000000000000 electrons!) ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺

2. Current The number of Coulombs flowing past a point in the circuit every second. I = Q/t ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ A I’m counting how many coulombs of electrons go past me every second 1 Amp = 1 coulomb per second

3. In a series circuit Current is the same at any point in the circuit 2.5 A

4. In a parallel circuit The current splits (total current stays the same) 2.5 A 1.25 A

5. Voltage(emf) ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ V I’m checking the difference in energy (per coulomb) between the 2 red arrows 1 Volt = 1 Joule per coulomb

6. Voltage (p.d.) ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ ☺ V I’m checking the difference in energy (per coulomb) before and after the lamp 1 Volt = 1 Joule per coulomb

7. In a series circuit The sum of the voltages across the lamps equals the voltage across the cells 9 V 3 V

8. In a parallel circuit In a simple parallel circuit, voltage across each lamp equals the voltage across the cells 5 V

9. Resistance Measures how difficult it is for current to flow. Measured in Ohms (Ω) VA Resistance = voltage/currentR = V/I

10. Resistance of a lamp AV Resistance = voltage/currentR = V/I Vary the voltage and current using a variable resistor (rheostat). Plot a graph of resistance against current

11. Resistance of a lamp V(V)I(A)R(Ω) I(A) R(Ω)

12. Resistance of a lamp As the current in a lamp increases, it gets hotter, and its resistance increases. Why?

13. Ohm’s Law V = IR V R I X

14. Power The amount of energy used by a device per second, measured in Watts (Joules per second) VA Power = voltage x currentP = VI

15. Power The amount of energy used by a device per second, measured in Watts (Joules per second) VA Power = voltage x currentP = VI ☺ Can you copy this please?

16. Example A 200 W television is plugged into the 110V mains. What is the current in the television? P I V X

17. Example A 200 W television is plugged into the 110V mains. What is the current in the television? I = P/V = 200/110 = 1.8A P I V X

18. Example A kettle uses 240V and 8A. What is its power? P I V X

19. Example A kettle uses 240V and 8A. What is its power? P = VI = 240x8 = 1920W (=1.9kW) P I V X

21. Electric symbols

23. Cell and battery of cells

25. Lamp

27. Switch

29. Ammeter

31. Voltmeter

33. Resistor

35. Variable resistor (rheostat)

37. Thermistor Resistance decreases with increasing temperature Temp Resistance

39. Light-dependent resistor (LDR) High resistance in the dark but a low resistance in light

41. Diode Allows current to flow in one direction only (from + to – in the direction of the “arrow)

43. Captain Jack Sparrow smoking a cigar

45. Two cowboys on a tandem

47. Two fried eggs in a frying pan

49. 3 wizards looking down a well

50. Let’s try some MORE questions!